This invention relates to a portable health self-monitoring apparatus, and more particularly to an instrument for converting data input concerning work expended, pulse rate, and blood pressure into data indicative of various physiological parameters such as heart work index, total peripheral resistance to blood flow, and caloric need. In addition, the invention relates to a carrying case for the aforesaid instrumentation which converts into an exercise stool.
In recent years, more emphasis has been placed on health care, and particularly on home health care.
Additionally, particular attention is now being given to cardiovascular fitness. Various types of instrumentation are now available in the domestic market for measuring blood pressure, pulse rate, and heart rate.
This is pertinent raw data, but unless it is combined with other data and taken at precise times in conjunction with a controlled exercise program on a periodic basis it is not particularly helpful. A discussion of various physiological parameters may be helpful in understanding the problem.
First of all, one should be aware of the term “heart work index” which, as used herein, is a measure of the heart's ability to develop an economy of effort to accomplish a prescribed workload. Also, the heart work index estimates a tone in the myocardium (middle muscular layer of the heart wall) that produces more cardiac output. Over a period of time a decrease in the heart work index shows an improvement in the ability or efficiency of the heart muscle to perform a foot pound of body work. Heart rate recovery is the key to determining the heart work index in that it depicts the quickness with which the heart muscles restore the heart to its pre-stress status and also expresses the ability to quickly eliminate the toxic elements and waste that accumulated during the stress period.
The heart work index formula as utilized in the present invention is:
  HWI  =            [                                    HR            1                    /          WT                +                                            HR              2                        +                          HR              3                                            Ft            ⁢                                                  ⁢                          Lbs              .                                          ]        ⁢    100  
Where:                HWI=heart work index        WT=weight of the subject        HR1=resting heart rate        HR2=heart rate immediately after exercise        HR3=heart rate 1 min. 30 sec. after exercise        S (measured in ft. pounds)=the number of steps onto a one foot bench×the body weight×5 (complete step up and down of both feet onto and from bench=1 count        J (measured in ft. pounds)=distance in feet×body weight×0.8 (walking or jogging)        H (measured in ft. pounds)=the number of steps (the number of times the left foot lands)×3×body weight×0.8 (walking or running in place)        
Heart rate immediately after exercise (HR2) should be taken within the first ten or fifteen seconds after the exercise routine is completed. Thus, the heart rate should be established during a relatively short span of sensing, because the heart rate tends to decrease at a faster rate after about twenty seconds into post stress period.
Total peripheral resistance which, as used herein, is the resistance to blood flow can be closely estimated by gauging the recovery ability of the heart rate during the post stress period. The change in the heart rate from a time immediately after exercise and a time one minute and thirty seconds after stress period also is indicative of the tone of the myocardium. Rapid recovery of the left ventricle is proportional to the economy of effort of the heart. Also, rapid recovery is proportional to ejectable force of the left ventricle which is inversely related to total peripheral resistance.
The formula for total peripheral resistance is:                TPR=mean blood pressure divided by heart rate recovery expressed as a percentage.        
The formula used to calculate mean blood pressure in medical schools and nursing schools is systolic blood pressure minus diastolic blood pressure divided by three then added to the diastolic blood pressure. The heart rate recovery expressed as a percentage is the difference between the heart rate immediately after a three minute exercise and the heart rate after one minute and thirty seconds following the exercise period divided by the resting heart rate and all multiplied by one hundred.
Thus the entire formula for total peripheral resistance is written as:
  TPR  =                    [                                            SBP              -              DBP                        3                    +          DBP                ]            ÷              HR        4              ×    100.  
where:                SBP=systolic blood pressure        DBP=diastolic blood pressure        HR1=resting heart rate        HR2=heart rate immediately after three minutes exercise        HR3=heart rate one minute and thirty seconds after completion of the three minute exercise        
      HR    4    =                              HR          2                -                  HR          3                            HR        1              ×    100  
Caloric usage is another parameter which is very helpful to persons on an exercise or exercise/diet program. Diet programs are interrelated with caloric intake and usage. Therefore it is advantageous to be able to determine caloric usage during a particular exercise regime. The pertinent formula for determining caloric usage is to divide the work in foot pounds done by 3,172 to obtain the calories used. Thus, if a person is stepping up onto a one foot high stool repeatedly, the formula for determining the calories used is to multiply the number of steps by the weight of the person, all of which is divided by 3,172. Likewise, if the person is jogging, the distance in feet is multiplied by the weight of the individual times 0.8 (coefficient of friction), all of which is divided by 3,172. Thirdly, if the person is jogging in place, the formula for determining caloric usage is. caloric usage equals number of left steps times 3 times weight times 0.8 divided by 3,172.